Electronic mobile devices such as smartphones, for example, are increasingly used by people to effectively digitize paper documents by capturing a photo image of each such document using a camera that is typically coupled with and/or integrated with the electronic mobile device itself. For example, if a user goes out to eat at a restaurant for a meal, he or she may prefer to keep a digitization of the check and/or receipt rather than having to deal with original paper copies.
Due to the nature of traditional image capture processes, however, the use of an original picture is not ideal. For example, such captured images frequently include parts of the background, which unnecessarily increases the corresponding file size and also causes undesirable problems with subsequent image processing operations such as perspective transform and optical character recognition (OCR). Moreover, attempting to capture an image of a document without the background by adjusting the camera position and zoom is a tedious and inefficient process.
Accordingly, there remains a need for improved techniques for detecting a document's boundaries in a captured image thereof and potentially removing non-document regions therein.